Heating device

ABSTRACT

The invention relates to a heating device comprising at least one heat exchanger that spirals helically around a spiral axis, is traversed by a heating medium and is configured as a flat tube comprising ends of the spiral on the feed flow and return flow sides and heating medium connections, said heat exchanger defining a corresponding spiral-shaped flow opening. A cap-type sealing housing is attached in a fluid-tight manner to at least one end of the spiral and the heating medium connection is situated on the housing. At least one end of the spiral is obliquely truncated in relation to the spiral axis and the end of the sealing housing on the spiral side has a corresponding inverse oblique configuration. Preferably, the heating medium connection on the cap-type sealing housing runs in the direction of the spiral axis.

The invention relates to a heating device according to the preamble of claim 1.

A heating device of the type specified initially is known from DE 38 15 647 A1. This consists of at least one heat exchanger that spirals helically around a spiral axis, is traversed by a heating medium (in this case a coolant) and is configured as a flat tube comprising ends of the spiral on the feed flow and return flow sides and heating medium connections, said heat exchanger defining a corresponding spiral-shaped flow opening, wherein a cap-type sealing housing is attached in a fluid-tight manner to at least one end of the spiral and the heating medium connection is situated on said housing. FIG. 1 of DE 38 15 647 A1 shows a solution with a single spiral and FIG. 2 shows a solution with an intertwined double spiral.

Another heating device is known from DE 102 11 489 C1, wherein such heating devices fitted with double or multiple spirals as heat exchangers are particularly intended for higher power ranges. The two wound heat exchangers formed as flat tubes are intercalated in said heating device by welding to sealing walls (so-called plates) provided on both sides, in which corresponding indentations are made with reference to the gradient of the two wound flat tubes or the heat exchanger, wherein the open ends of the obliquely truncated flat tubes corresponding to the gradient there are connected to inlet and outlet openings in the plates (the oblique cut is necessary from the production technology aspect since the plates are produced by deep drawing so that a 90° angle is not possible). These plates must also be configured as hollow plates in order to form feed and return flow chambers with feed and return flow connections for heat consumption circuits to be connected.

For the sake of completeness, reference is also made to a heating device according to DE 10 2004 005 048 A1.

It is the object of the invention to simplify these relatively complex designs, especially to avoid hollow covering plates over the entire cross-section of the heating device and optionally to ensure as uniform as possible exposure of parallel-guided heat exchangers or flat tubes, and specifically associated with the proviso to provide overall more favourable manufacturing conditions.

This object is achieved with a heating device of the type specified initially by the features specified in the characterising part of claim 1.

According to the invention, it is therefore provided that at least one end of the spiral is obliquely truncated in relation to the spiral axis and the end of the sealing housing on the spiral side has a corresponding inverse oblique configuration, wherein the heating medium connection on the cap-type sealing housing is preferably aligned to that it is oriented in the direction of the spiral axis.

In other words, the inlet and outlet openings at the spiral ends are arranged in a plane oriented obliquely in relation to the flow direction, to which the sealing or distributor housing, cut correspondingly but in the opposite direction, is attached, i.e. according to the invention, an obliquely oriented plane (connecting plane) is provided between the spiral end the sealing housing. Particularly from the production technology point of view, this oblique cut facilitates the connection of the sealing housing to the spiral end since all the connecting edges are accessible to a welding process, for example, without further spreading of the spiral, which was not possible in spirals in the sense of DE 102 11 489 C1 or DE 10 2004 005 048 A1 since the flow gap (heating gas flow gap) is relatively narrow in contrast to DE 38 15 647 A1.

Starting from this assumption, the sealing or distributor housing in side view are preferably configured substantially as right-angled triangles, whose hypotenuse forms the connecting side for the spiral ends and the heating-medium connection is located on their larger side.

The solution according to the invention is particularly intended for heating devices whose heat exchangers consist of at least two tube spirals for which it is therefore necessary to connect the participating flat tube spirals to one another hydraulically, seal them at their ends and provide common heating medium connections. However, it has been shown that the solution according to the invention is also suitable for heating devices which manage with only one spiral tube (that is one heat exchanger), for example, as a result of lower power requirements.

However, in heating devices wherein at least two helically spiralling heat exchangers which are guided parallel to one another and intertwined with one another are provided and wherein the sealing housing is configured as a distributor housing and is attached in a liquid-tight manner to the ends of the spirals, it is furthermore particularly preferably provided according to the invention that the ends of the spirals of the heat exchangers are each arranged in pairs flush and adjacent to one another, wherein in each case edges of their adjacently extending walls are connected to one another in a liquid-tight manner.

Unlike DE 38 15 647 A1, the heating device according to the invention particularly has the function of a heating boiler (see again on this matter DE 102 11 489 C1 and DE 10 2004 005 048 A1). Accordingly, it is preferably provided that that the at least one heat exchanger encloses a combustion chamber which, when viewed in the direction of the spiral axis, is delimited by respectively one sealing wall wherein a housing formed from a jacket part and the sealing walls surrounds the heat exchanger forming an exhaust gas chamber.

Apart from the fact that the cap-type sealing or distributor housing with its heating medium connections can first be manufactured independently of the heat exchanger spirals, and on the spirals themselves, apart from the liquid-tight connection of their adjacently running walls, there is no need for overflow openings or other particular manufacturing interventions, the configuration of the two heat exchanger spirals according to the invention as an essential element of the heat exchanger, fulfils a double function, i.e. firstly the hydraulic connection of the two spirals is made by the distributor housing which at the same time forms a convenient approach for the. feed flow and return flow connections preferably oriented in the direction of the spiral axis and secondly, the heating medium return flow is fed directly and in a concentrated manner to the two spiral ends or on the feed flow side, the heating medium feed flow is removed accordingly in a concentrated manner. In addition, since the previous hollow plates as in DE 10 2004 005 048 A1 can be eliminated, no gradient-matched connection deformations for the spiral ends need be taken into account at the sealing walls for the combustion chamber, but merely simple reach-through openings for the heating medium connections which, as mentioned, run parallel to the axis of the combustion chamber on the heating device.

In the section viewed transversely to the direction of flow of the heating medium, the cap-type sealing or distributor housing is configured as substantially corresponding to the opening cross-section of the two spiral ends, i. e. the two cap-type distributor housing occupy virtually no additional space and in this respect, constitute merely a continuation of the spiral ends on the external contour side.

Furthermore, the distributor housing is arranged in relation to the return flow supply and also the outflowing feed flow starting from the lower flat tube or the lower flat tube spiral with its hypotenuse ascending.

In order to optimise the flow distribution inside the distributor housing in relation to the spirals, the sealing walls of the distributor housing opposite to the attached spiral ends are advantageously configured as concavely curved or concavely profiled on the inside.

At the same time, the sealing or distributor housing can be configured in the form of deep-drawn parts or also in such a manner that the distributor housings are each formed from a sheet metal blank which is to be folded and corresponds to their final shape. It is preferably provided that the sealing housing is configured in the form of a cast part, in particular a precision cast part.

Other advantageous further developments are obtained from the dependent claims.

The heating device according to the invention including its advantageous further developments according to the dependent claims will be explained in detail hereinafter with reference to the drawings of exemplary embodiments:

In the figures (partially schematic)

FIG. 1 shows a simplified section through the actual heat exchanger of the heating device;

FIG. 2 shows a corresponding section according to FIG. 1 in the embodiment according to the invention;

FIG. 2A shows a sheet metal blank for forming distributor housings;

FIG. 3 shows a perspective view of one end of the double spiral;

FIG. 4 shows the end of the double spiral according to FIG. 3 with attached distributor housing (not yet welded on);

FIG. 5 shows a diagram corresponding to that of FIG. 4 showing one spiral end in a contour-matched embodiment of the distributor housing (precision casting);

FIG. 6 shows an oblique section along the line A-A in FIG. 5;

FIG. 7 shows a perspective overall view of the heat exchanger of the heating device;

FIG. 8 also shows a perspective and simplified view of the entire heating device without external accessories;

FIG. 9 shows a perspective view of a heat exchanger formed from only one spiral with attached sealing housing; and

FIG. 10 shows an embodiment of the sealing housing made of precision casting.

According to the exemplary embodiment as before and with reference to FIGS. 1 to 8, the heating device according to the invention consists of two helically spiralling heat exchangers 1, 2, traversed by a heating medium and defining a correspondingly spiralled flow gap S for heating gases, which heat exchangers are guided parallel to one another and into one another as flat tubes F or are arranged so that they are screwed into one another to a certain extent.

The heat exchangers 1, 2, which thus form a double spiral, each have two spiral ends 3, 4; 3′, 4′ on the return flow and feed flow sides (see FIGS. 1, 2), wherein the two heat exchangers 1, 2 in hydraulic communication with one another in relation to heating medium connections 5 enclose a cylindrical combustion chamber BR which, when viewed axially (i. e. in the direction of the spiral axis), is delimited at both ends by a sealing wall 6, 7, of which one serves as a connecting wall 6 for a burner B. A housing 8 formed from a jacket part 9 and the walls 6,7 (shown only schematically in FIG. 1), encloses the two heat exchangers 1, 2 to form an exhaust gas chamber 11 provided with an exhaust gas connection 10 (see FIG. 8), which is also only indicated schematically in FIG. 1.

For such a heating device having two spirals it is now essential that the spiral ends 3, 4, 3′, 4′ of the two flat tubes F forming the heat exchangers 1, 2 are each arranged in pairs flush and adjacent to one another and the edges R (FIG. 3) of their adjacently extending walls W are connected to one another in a liquid-tight manner, preferably welded (the thick black line represents the welded seam).

For the purpose of hydraulic connection of the two flat tubes F, the spiral ends 3, 4, 3′, 4′ on the feed and return flow sides are jointly attached in a liquid tight manner to respectively one cap-type sealing housing 12 which is open toward the flat tubes F and is configured as a distributor housing, each distributor housing being provided with respectively one of the heating medium connections 5.

As can be seen from FIGS. 2 to 5 in particular, the cap-type distributor housings are configured in the section viewed transversely to the direction of flow of the heating medium as substantially corresponding to the opening cross-section of the two spiral ends 3, 4, 3′, 4′ in order to take up as little space as possible.

Likewise with reference to FIGS. 4 to 6, the inlet and outlet openings 14 at the spiral ends 3, 4, 3′, 4′ are arranged according to the invention in a plane E oriented obliquely in relation to the direction of flow (see FIG. 2), to which the distributor housings cut correspondingly obliquely in the opposite direction are attached, i.e. preferably welded on.

Thus, in side view the sealing housings 12 substantially form right-angled triangles whose hypotenuse H forms the connecting side for the spiral ends 3, 4, 3′, 4′, the relevant heating medium connection 5 being disposed on the larger side K in each case.

At the same time, in order to optimise the inflow and outflow relationships for the heating medium, the sealing housing 12 is preferably arranged with reference to the return flow guidance and FIG. 2, starting from the lower flat tube F or the heat exchanger 2, with its hypotenuse H ascending.

For the same reason, i.e. for optimisation, the sealing walls 13 of the distributor housing 12 opposite to the spiral ends 3, 4, 3′, 4′ are configured as concavely curved or concavely profiled on the inside, as is illustrated in the oblique section view according to FIGS. 6 and 10.

The previously explained sealing housing 12 can easily be manufactured as deep-drawn parts on account of their simplicity but can also be formed from a sheet metal blank which is to be folded to correspond to their final shape, one of which is shown in FIG. 2A for a sealing housing 12 which is triangular in side view, this being the preferred shape, since an optimised distribution of the return flow and the feed flow of the heating medium at the two spiralled heat exchangers 1, 2 is thereby obtained with reference to FIG. 2. As already mentioned, however, it is also possible to produce or form the distributor caps of precision casting, for example, wherein the respective heating medium connection 5 is advantageously formed in one piece at the same time (see FIG. 10).

The same applies to heating device whose heat exchanger consists of only a single flat tube spiral 1 which is illustrated in FIG. 9 for completeness, wherein this representation comprises the embodiment according to the invention in which the spiral ends 3, 4 of the flat tube F on the return and feed slow sides are obliquely truncated and the sealing housing 12 attached thereto has a corresponding inverse obliquely truncated configuration, forming a flat triangle in side view. FIG. 10 shows a preferred embodiment of the sealing housing 12 as a precision casting including the heating medium connection 5.

REFERENCE LIST

-   1 Heat exchanger -   2 Heat exchanger -   3 Spiral end -   3′ Spiral end -   4 Spiral end -   4′ Spiral end -   5 Heating medium connection -   6 Sealing wall -   7 Sealing wall -   8 Housing -   9 Jacket part -   10 Exhaust gas connection -   11 Exhaust gas chamber -   12 Sealing housing -   13 Sealing wall -   14 Inlet and outlet opening -   B Burner -   BR Combustion chamber -   E Plane -   F Flat tube -   H Hypotenuse -   K Side -   R Edge -   RL Return flow -   S Flow gap -   VL Feed flow -   W Wall 

1-12. (canceled)
 13. A heating device, comprising at least one heat exchanger that spirals helically around a spiral axis, is traversed by a heating medium and is configured as a flat tube comprising ends of a spiral on a feed flow side and a return flow side and heating medium connection, said heat exchanger defining a corresponding spiral-shaped flow opening, wherein a sealing housing is attached in a fluid-tight manner to at least one end of the spiral and the heating medium connection is situated on said housing, wherein at least one end of the spiral is obliquely truncated in relation to the spiral axis and an end of the sealing housing attached to the spiral has a corresponding inverse oblique configuration.
 14. The heating device according to claim 13, wherein at least two helically spiralling heat exchangers are guided parallel to one another and intertwined with one another, wherein the sealing housing is configured as a distributor housing and is set in a liquid-tight manner against ends of the spirals, wherein the ends of the spirals of the heat exchangers are each arranged in pairs flush and adjacent to one another, wherein edges of adjacently extending walls are connected to one another in a liquid-tight manner.
 15. The heating device according to claim 14, wherein the edges are connected flush to one another.
 16. The heating device according to claim 15, wherein the edges are welded to one another.
 17. The heating device according to claim 13, wherein the heating medium connection on the sealing housing is aligned so that it is oriented in the direction of the spiral axis.
 18. The heating device according to claim 13, wherein the sealing housing in side view and therefore perpendicular to the spiral axis is configured substantially as a right-angled triangle, wherein the hypotenuse of the triangle is connected in a liquid-tight manner to an end of the spiral.
 19. The heating device according to claim 18, wherein the heating medium connection is arranged on a larger side of the triangle.
 20. The heating device according to claim 13, wherein the sealing housing and the heating medium connection are configured in a form of a cast part
 21. The heating device according to claim 13, wherein the sealing housing and the heating medium connection are configured in a form of a precision cast part.
 22. The heating device according to claim 13, wherein the sealing housing is configured as sheet metal parts and the heating medium connection is configured as connecting pieces set against the sheet metal parts.
 23. The heating device according to claim 13, wherein the sealing housing is configured in a form of a deep-drawn part.
 24. The heating device according to claim 13, wherein according to a section viewed transversely to a flow direction of the heating medium, the sealing housing is configured as substantially corresponding to at least one spiral-end opening cross-section.
 25. The heating device according to claim 13, wherein sealing housing sealing walls opposite to the spiral ends are configured as concavely curved at least on a side attached to the heating medium.
 26. The heating device according to claim 13, wherein at least one heat exchanger encloses a combustion chamber which, when viewed in a direction of the spiral axis, is delimited by respectively one sealing wall, wherein a housing formed from a jacket part and sealing walls surrounds the heat exchanger forming an exhaust gas chamber. 